Where does “päiväin” come from?

päiväin (Ingrian) comes from Ingrian päivä, from Proto-Finnic päivä, from Proto-Uralic päjwä, from Proto-Uralic päje.

Ancestry of “päiväin”, step by step

StepLanguageWordMeaning
1IngrianpäiväA day; An afternoon
2Proto-Finnicpäiväsun; day
3Proto-Uralicpäjwä? warmth; ? sun; ? fire
4Proto-Uralicpäje—
Every word from Proto-Uralic päje →Every word from Proto-Uralic päjwä →Every word from Proto-Finnic päivä →